# Definition:Concatenation (Formal Systems)

## Definition

Let $\AA$ be an alphabet of symbols.

Concatenation is the process of placing elements of $\AA$ and words in $\AA$ next to each other to form a longer word.

## Example

Let $a, b, c \in \AA$.

Then concatenating $b$ to $a$ results in the word $ab$, and concatenating $c$ gives the word $abc$. Concatenating $b$ then gives $abcb$.

Concatenating $aba$ to $aabcba$ gives the word $aabcbaaba$.

## Linguistic Note

The word concatenation derives from the Latin word catena for chain.

However, the end result of such an operation is not to be confused with a (set theoretical) chain.